1. Field of the Invention
This invention relates generally to power-up control circuits, and more particularly to a power-up control circuit having an architecture that senses a rising and falling supply voltage while consuming no current during normal operation.
2. Description of the Prior Art
Circuits, products and processes that presently employ one or more dedicated power-up control circuits are problematic in that once the circuit(s), product(s) and/or process(es) become fully operational following the initial power-up, current continues to be consumed, and therefore wasted, by the one or more dedicated power-up control circuits. These known power-up circuit solutions and architectures require current flow throughout the power-up circuit(s) at any time the associated circuit, product, or process is in operation; and are limited in that there is presently no power-up circuit solution that requires no current during normal operation while still being able to sense a falling supply voltage.
In view of the foregoing, a need exists for a power-up control circuit that requires no current during normal operation while maintaining sense on the supply voltage, regardless of whether the supply voltage is rising or falling.
The present invention is directed to a power-up control circuit architecture that utilizes zero current under normal operation. The power-up control circuit will sense a common supply voltage, Vcc, and turn an output on and off at a desired threshold voltage, providing a substantially faster on/off switch than that achievable solely by sensing the common supply voltage.